This invention relates to a fusion apparatus, and more particularly to a fusion apparatus for joining or splicing optical fibers in axially aligned end-to-end relationship.
Known fusion splicers fall into three general categories varying in complexity and, accordingly, widely varying in expense. The first general type of alignment mechanism for a fusion splicer is known as a V-groove apparatus. In the V-groove apparatus, first and second optical fibers are aligned on the basis of the outer diameter of the respective fibers. That is, the presumption with this alignment mechanism is that the core of a fiber is centralized relative to the outer diameter. Therefore, alignment of the outer diameters of the fibers theoretically will align the cores in an effort to maximize transmissibility through the completed splice.
A second general category of apparatus for aligning optical fibers is referred to as a "local launch and detect system". Apparatus of this general type bend the light fiber at an area removed from the splice region so that a beam of light can be effectively transmitted through a sidewall of the optical fiber into the core region, transmitted through the proposed splice connection, exit through a sidewall of the second optical fiber at a second bend area, and monitored by suitable sensing means. Typically, a microprocessor is used to control precision movement of the optical fiber(s) along the X and Y axes in order to maximize the intensity of the light passing through the proposed splice region from the first fiber to the second fiber. Although deemed to be more accurate than the V-groove apparatus since the light passing through the splice region is monitored, this apparatus accordingly increases dramatically in cost due to its complexity. The overall unit is also much larger in order to accommodate the local launch and detect system.
The third general category of fusion splicers operates on the principle of "profile alignment". Rather than bending the optical fibers at an area remote from the splice region as in the local launch and detect system, the profile alignment system illuminates the ends of the respective fibers and maximizes alignment of the cores based on the reflected profiles. Again, although this apparatus is more accurate than the V-groove apparatus, it has a corresponding downside related to the complexity and increased cost of such a unit.
In each of the above types of apparatus, it is necessary to securely clamp the optical fibers during alignment and subsequent fusion procedures. Typically, spring biased clamping members exert a predetermined clamping force on a fiber. Even though many of the fusion apparatus are extremely complex as described above, the prior art has failed to adequately resolve the problem of accommodating various sizes of optical fibers. For example, the glass portion of these fibers has a diameter approximating 125 microns where the glass portion, or bare fiber as it is sometimes called, comprises a glass core and surrounding glass cladding. A multimode fiber has a core of approximately 60 microns and a single mode fiber has a core of approximately 8 microns. A plastic layer surrounds the glass portion and can vary widely in thickness. Therefore, the clamping members must be able to accommodate a range of diameters approximating 125 to 900 microns.
Portable fusion splicers employ a DC or AC voltage source that is effectively stepped-up to higher voltages through use of a transformer. Since extremely large voltages are required to establish an arc between the electrodes, the overall size of the fusion unit increases to accommodate the enlarged transformer necessary to raise the voltages to these levels.
The subject invention is deemed to overcome the noted problems of the prior art and others while providing a self-contained, effective fusion splicer apparatus that is substantially reduced in size without the high costs associated with more complex units. On the other hand, the subject invention represents a vast improvement over the most basic fusion splicer units.